Attachment spindle clamp



Sept. 6, 1932. J KEARNEY 1,875,739

ATTACHMENT SPINDLE cLAlP 0 12 Filed April 24, 1923 5 shqets-sheet 1 1N VBNTOR BY J ATTORNEY Sept. 6, 1932. E. J. KEARNEY ATTACHMENT SPINDLE CLAMP Original Filed April 24, 1925 s Sheets-Sheet 2 INVENTOR.

ATTORNEY E. J. KEARNEY 1,875,739

ATTACHMENT SPINDLE CLAIP Original Filed April 24, 1923 IN VENTOR M J it? 40 mm A TTO R/VE Y Patented Sept. 6, 1932 UNITED ST TES- EDWARD .1. xmnny, or .wnuwnros'ri, Wisconsin. nssie toa r KEARNEY a lrimcxnn conronnrroiv, .or WEST:ALIIS,V1WISCONSIN ATTACHMENT SPINDLE CLAMP 1927. Serial This invention relates toimprovements in spindle clamps. "It is particularly :adapted for use in a machine tooliattachment forming the subject matter of. a companion application 634,292, filed April 24,1923, of which this case isa division: a I

'The machine tool attachment. forming the subject matter of the above entitled parent application is adapted to perform .many functions, including that of a ;..'dividing en'- gine, with :great accuracy, and the general purpose of this invention, together withv that claimed in the parent application and other divisional applications, a is :to promote accuracy in a device of this characters The specific object ofithe present invention is to promote accuracy by providing a spindle or work table clamp acting directlyron the spindle or work table-or a part rigidly connected therewith in such manner that there is no tendencyto move :the work table in the adjustment of the clamp; The "loca- 'tion and construction of the-clamping device 1 are both of the utmost importance in achieving this end. x g

It is a further ob ect ofuthe mvention to provide, in a devicehavingwan unusually large number of adjustments, .a spindle clamp which may convenientlyrbe manipu- "lated in any position of spindleadjiustment.

In the drawings:' s Figure 1 is a plan viewofthecdevice. embodying this invention. l

Figure 2is a section takenfonfthe-line 2-2 ofFigurel. Figure 3is a section taken; on: line .3 13 of Figure 1. i i p v: Figure 4 is a detail new in plan ofanexpansible clamp ring and expander.

Like parts are'identified zbysthe same reference characters throughout. the several "views.

My deviceas shown in the drawings 'corporated in a machine tool attachment known as a dividing head whichcomprisesa base 10 provided with a numbercofspaced upstanding ears15," 16, i 17, .and 18, wh ch register with a" number .ofacomplementary knuckles 19, 20,-.and 21 connected with .a

this application fl1edM ayt28;

,The frame 11 provides at atapered bearing opening Within'whichpa cor-respondingly formed spindle 5O .lS journa-led. The

largerend of thetaper is normally natathe front or. working end of the dividinghead structure; Where the terms front and rear are used hereintliey maybe .consi'deredito refer .to the working-end, thatyisito say, the left inFig. 3 as thefront. A platen ortable .51having a workingsurface 52 may ibe and, in the present embodiment of thisuin-vention, is an integral part of spindlel5'0. Therplat en. or .table 51projects axially fromwa close fitting sleeve 53 which is integral withiframe 11. The projection of the table from isaid sleeve is suflicient to provide for :the slots shown I at 54: wherein the heads of bolts: may be introduced to secure work in an operatiize position upon said, table "or platen. .xThis construction is of .advantageibecausewhen the .device is operated in the'position iniwh ich it appears in the accompanyingizdrawings :the T slots permit work to 'loev clamped rigidly 'to the spindle, and, when the frame .11 is ment which isuwidely knownin theart. 11

have providedin the framelcastingllan integral lip portion .55 between which {and the sleeve 53 is formed ahtrough. 56 adapte'd to receive oil 1 and chips when platen J5'l.ilS in use as a table. 1 A packing ring i57 win .a suitable groove im the table wipes the interior surface of sleeve :53 and ipreventsmcoolant and chips from reaching the interior 'imech- Lanismof :this' device.

, Rigid'ly connected to the rear of table 51 to comprise in eifect apar't'thereof is aworm .gear .60 which is; preferably peripherally recessed as shown in Figure 3, to receive the corresponding shoulders 61 .of 'the taible. A

plurality of axially extending 'pins"*62 j secure the tablejandworm gear ;,60 together. These parts ,are separatelymade only for convenifence in manufacture. The worm' gear, 11s i driven by a worm 63 which, in tu'rn, is actutheradvantage that it tends to co-operate ated from the shafts or through mechanism hereinafter to be described.

A nut 65', threaded to the end of the tapered spindle 50, maintains the spindle properly positioned within its bearing. Where the use of a center is desirable, the

center pin 66 which tapers rearwardly may be introduced into the axially extending and correspondingly formed opening 67 of spindle wherein it is retained frictionally and by the pressure of the work. we v It will be noted that in the present embodiment of this invention theworm gear v comprises an annulus which is fast to the spindle adjacent the Working end thereof and at the peripheryof said end. When it is desired to lock the spindle'in any given position of rotative adjustment, the inner surface 68 of the annular gear 60 is arranged to receive the clamping pressure of an expansible split ring 70. The extremities 71 of said ring converge symmetrically rearwardly as shown in Figure 4,, and between them is fitted the wedgeshaped-head 72 of a bolt or pin 73. The rear extremityi'e of said pin is extended through an apertured upstanding ear 7 5 between which and the .body of frame casting 11 is confined a nut 76 in threaded engagemen with bolt 7 8. 1

The arrangement is such that bythe rotation of nut 76 the bolt 7 3 may be advanced or retracted axially to or from the platen. WV-hen the bolt is retracted as aforesaid, its wedge-shaped head 72 acts uponuthecorrespondingly converging end faces '71 of the split ring 7 0 and thereby expands said ring symmetrically into contact with the inner surface 68 of the annular gear 60. In this Way, the gear, together with the spindle and all related parts maybe frictionally bound against rotational movement in either direction'and inasmuch as the ring must expand equally in'opposite directions from the center lineof the device there Will obviously be no tendency for the clamping operation to cause any rotational movement of the spindle. Such an arrangement makes for accuracysince an adjustment once obtained will not bedisturbed when the parts are clamped. i

v. Thisparticular type of clamp has thev furwith the tapered spindle andspindle bearing to produce an unusually rigid clamping action. The wedge portion'72 has sides which converge rearwardly.- Hence, the pin is nation with a spindle rotatable in a tapered moved toward the small end of the spindle .to expand the clamping ring 70. Obviously,

this ring will pass through a succession of degrees of frictional engagement with the spindlebefore the ultimate desired clamping pressure is reached. The ringis floated'within its chamber and should it move at all in effecting clamping action, it could only move inwardly with the pin. 1 In such a case, the spindle would be urgedin the direction of the smaller end of its tapered hearing, but such urging could only result in movement if the spindle had previously been axially displaced from the desired clamped position. v Thelocation of the clamp within a recess in the rear face of the-platen is such that the clamp is protected from all possibility of accidental displacement, Additionally, the clamp is made more effective by virtue of its action directly on a portion of the platen near the outer periphery thereof. It will readily be appreciated that with comparatively l ge a s- & g ves amqant f damp: ing pressure will be far more effective to hold the spindle than would be the case if the radius-were smaller. -At the sameitime, the large radius at which the clamp operates has the effectof minimizing any possible displacement due to the clamping operation. In other words, even if some lessbalanced form of clamp than that herein disclosed were applied in a similar relation to the platen, a given displacement ofthelclamp would produce less angular displacement of exact verticalcenter ofthe device and'is,

therefore, clearly accessible'from all sides thereof, Even when the platen is tilted to a horizontal position, as shown in dotted lines in Figure 3, the nut 76 for adjustment of the clamp will still be readily-accessible. 1

It will be understood thatthe invent-ion herein disclosed iscapable of a variety of different equivalents, each, of which it is desired to protect :if withinthe scope of the claims. 7 V c What is claimedis 1. In a machine tool, attachment, the combination of a spindle rotatable in a tapered bearing, a spindle clamp comprising an excluding a pin axially movable parallel with the spindle axis in the direction of the small end ofthe spindle bearing to expand the ring.

2. In a -machine-tool attachment, the combination with a spindle rotatable in a tapered bearing to expand the ring.

4. A machine tool attachment including the the platen than would be the case if the 9,9

pansible ring andiring exp'andingmeans -in- I combination with a work supporting member provided with a tapered bearing and an annular recess concentric therewith, of an expansible ring floating Within said recess and provided with angularly formed end faces converging in the direction of the smallend of said bearing, a Wedge axially movable parallel to the spindle axis and confined against rotation about said axis, said wedge being disposed in the end faces of the ring and adapted to move toward the small end of said bearing for the expansion of said ring.

5. In an attachment for machine tools, the combination of a base, a frame adjustable on said base about a horizontal axis, a spindle rotatably supported from said frame in a tapered bearing having its axis at right angles to said horizontal axis, a member fixed on said spindle and providing an annular surface concentric with said bearing, and clamp means cooperative with said annular surface to fix said spindle against rotation and simultaneously to urge said spindle in the direction of the smaller end of said tapered bearing.

6. In an attachment for machine tools the combination of a base, a frame adjustable on said base about a horizontal axis, a spindle rotatably supported from said frame in a tapered bearing, and axially at right angles with said horizontal axis, a driving gear fixed With said spindle for power movement thereof, said gear having associated therewith an annular surface concentric with the axis of a said spindle, an annular ring providing a surface complementary to said annular surface but normally disengagedtherefrom and means adapted to change the diameter of said ring whereby to frictionally engage said surfaces and simultaneously to urge said ring axially in the direction of the smaller end of said tapered bearing.

In witness whereof I hereto aflix my signature.

EDWARD J. KEARNEY. 

